Technical Field
Embodiments of the invention relate generally to motor system control, such as in a vehicle.
Discussion of Art
In the mining industry, large off-highway vehicles, “OHVs”, may employ electrically motorized wheels for propelling or retarding the vehicle. In particular, OHVs typically include a large horsepower diesel engine in conjunction with an alternator, a traction inverter, and wheel drive assemblies housed within the rear tires of the vehicle. In operation, the diesel engine drives the alternator, which powers the traction inverter. The traction inverter includes semiconductor power switches that commutate the alternator output current to provide electrical power to electric drive motors, e.g., AC motors, of the wheel drive assemblies.
Such systems also include controllers and software that set the voltage passed to the traction inverters. This voltage, referred to as a “link voltage” is the main system variable in determining the operating mode and efficiency of the alternator, traction inverter, and traction motor. Link voltages typically vary based solely on the OHV motor speed and do not take into consideration factors such as ambient conditions.
As will be appreciated, changing the link voltage, however, can alter the fuel consumption of the system. It may therefore be desirable to provide a system and method that differ from existing systems and methods, for motor system control to reduce fuel consumption.